<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            outline: 0;
        }
        .clearfix:after{
            content: "";
            display: block;
            clear: both;
        }
        .green{
            background-color: green;
        }
        .orange{
            background-color: orange;
        }
        .w150{
            width: 150px;
            height: 150px;

        }
        .grail{
            /* 圣杯布局 padding 把左右左右侧边栏的位置让出来 */
            padding: 0px 150px;
            /* border: 1px solid #000; */
            /* overflow: hidden; */
        }
        .main{
            height: 100px;
            /* float:left; */
            
        }
        .grail main{
            float: left;
            width: 100%;
        }
        .grail .left{
            margin-left: -100%;
            left: -150px;
            position: relative;
        }
        .grail .right{
            margin-left: -100%;
            position: relative;
            right: -150px;
        }
        .left{
            float: left;
        }
        .right{
            float: right;
        }

    </style>
</head>
<body>
    <div class="layout">
        <h4>方法一：圣杯布局</h4>
        <section class="grail clearfix">
            <!-- 自适应 -->
            <main class="green">main</main>
            <aside class="w150 left orange">aside</aside>
            <aside class="w150 right orange">aside</aside>
        </section>
    </div>
</body>
</html>